The invention relates to a tunable digital filter arrangement as described in the chapter "Digital filters" on page 791 et seq. in the book by Tietze/Schenk entitled "Halbleiter-Schaltungstechnik" (Semiconductor Circuitry), 10th printing, Springer Verlag 1993.
The practical implementation of digital filter arrangements is described at length by Lacroix, Arild in: "Digitale Filter : eine Einfuhrung in zeitdiskrete Signale und Systeme" (Digital filters: An introduction to discrete-time signals and systems), 2nd printing 1985, pages 70 to 77, and is also to be found, for example, in WO 96/31001.
It was a disadvantage of the previously known digital filter arrangements that they were either not tunable at all or only by means of at least two parameters which were programmed and specified in a lookup table because the numerical relationships between the parameters are very complex and their calculation is too costly. Such two-parameter tunable filters, however, require a lookup table and an appropriate access control.